Lightest reaction wheel + probe core setup?

[Sharpy]

I pondered replacing my OCTO-based mini-probe cores with something smaller, but I realized the lightest cores don't have a reaction wheel. Still, maybe attaching a tiny reaction wheel would still get me ahead? What setup of either probe core with built-in reaction wheel or core + external wheel would be the lightest?

(or should I consider some tiny monopropellant tank and a set of RCS thrusters?)

Edited June 4, 2015 by Sharpy

[Prepper-Jack]

The small inline reaction wheel is as light as a thruster block. I usually use them inline with a couple of the cylinder batteries on my probes, and cover them all with solar panels.

[FancyMouse]

OKTO/HECS (not OKTO2) has built-in 0.3~0.5 torque which is good enough for small probes - no need to stick extra reaction wheel. It is 10kg heavier than OKTO2+small reaction wheel but it drains battery much slower. Considering solar panel savings (both mass and part count), I usually just pick OKTO/HECS to start with. I only do OKTO2 when it's a big unmanned probe that requires a dedicated reaction wheel anyway.

[cybersol]

I find HECS and RC-001S to both be decent compromises, along with okto2 plus a reaction wheel.

[Snark]

There's also the consideration that even the smallest reaction wheel is way over-torqued for small probes, especially if we're talking about something so tiny that you're concerned about what's lighter than a .1 ton probe core. Being over-torqued not only eats battery, but it can also cause SAS jitter/wandering.

I really wish reaction wheels had a tweakable power setting, like engine gimbal, instead of just on or off.

[MarvinKitFox]

I really wish reaction wheels had a tweakable power setting, like engine gimbal, instead of just on or off.

AMEN!

Squad, read this. it is a very needed feature!

[DBT85]

When I was playing around with some SCANSat probes, I had the smallest Octo, a small RCS tank and 4 thruster blocks, with a couple of single cell solar panels on and one of the round small batteries. It's so light that the Mono will take you all over the place if you want to go.